Louis pebbiee



(Medel.)

L. PERRIER.

-VAPUR TENSION MANOMBTBR. No. 246,905. Patented Sept. 1.3.1881.

SRSQQN mm t, u nv u e UNITED STATES PATENT GEEICE.

LOUIS PERRIEI,-OF PARIS, FRANCE.

VAPOR-TENSION NIANOM ETER.

SPECIFICATION forming part of Letters Patent No. 246,905, dated September 13, 1881.

Application filed August 12, 1880. (Model.) Patented in France December 24, 1879.

To all whom it may concern:

Beit known that I, Docteur LoUIs PERRIER, Conseiller-General of the Gard, (France,) residing at 83bis Rue Lafayette, Paris, France, have invented a new and useful Steam-Tension Manometer for Analyzing' Liquids and Studying Pressures, which is fully set forth and described in the following specification, and for which I have obtained a patent in France, bearing date December 24, 1879, No. 134,323.

The object of my invention is to determine the percentage of alcohol or other volatile substance in any given liquid by its boiling-point without the use of a thermometeror taking account of the barometric pressure, and it gives its indications by means of a column of inercury connected with a peculiarly-shaped bulb, in which is contained a small quantity of volatile liquid, the expansion ot' which, when immersed in the liquid to betested at its boilingpoint, causes the mercury to rise in the tube. The higher the boiling-point of the liquid to be tested the greater is the tension ot' the vapor formed by the volatile liquid in the bulb, and therefore the height of the mercury-column raised by the said vapor.

My manometer, illustrated by the accompanyingdrawings, Figure l, consists ofa glass pipe, M, tapered at its lower end, P, and dipping into a bulb which is soldered to the said pipe at K. The lower part of this bulb is lilled with mercury, above which there is a small quantity of a volatile liquid.

For better explaining the operation of my manometer, I will describe the apparatus with which it is chiefly used-namely, an alcoholmeter, as :represented by Fig. 2. This alcoholmeter determines the strength of an alcoholic liquid by comparing'the tension of its vapors with the tension of the vapor of the liquid inclosed in the bulb of the manometer. As shown in Fig. 2, the bulb of the manometer immerges in a small boiler, A, shut at the top by a cork, through which the manometer passes. The liquid, L, to be analyzed is introduced into this boiler and heated to the boiling-point by lighting a lamp placed under the boiler. The vapor formed by the liquid L enters the central pipe, r, of the refrigerator R, where it is partly condensed, the rest escaping at the top. It can be said that at the time when vapors commence to appear at the mouth of the discharge-pipe the tension of the vapors in the boiler balances the atmospheric pressure. These vapors communicate their temperature to the bulb of the manometcr and to the (constant) liquid contained therein, which (constant) liquid should be more volatile than the liquid to bc examined. The vapors generated in the bulb overcome the atmospheric pressure to which they are exposed through the mercury and raise a column of mercury in the pipe ot' the manometer until the atmospheric pressure and the weight of this column combined balance the tension ot the vapors of the constant liquid, hereinafter called the constant. Thus the tension of the vapors formed by the two different liquids can be compared. The tension of the liquid to be analyzed is equal to the barometric pressure, while the tension of the constant is equal to the barometric pressure plus the pressure corresponding to the height of mercuryraised: T=P+L. Because in every particular case the barometric pressure on the two liquids is the same, it can be left out of consideration, and the height of the mercury h gives a direct measure for the tension T ot' the constant, or for the temperature at which the liquid in the boiler evaporates. It is therefore only necessary to ascertain by successive experiments the value of h for some exactly known liquids, and to mark the corresponding percentage of alcohol or other degree of concentration on the manometer, in order to Iind afterward the concentration of unknown liquids from the height of mercury raised in the manometer. For instance, if I have a liquid containing exactly ten per cent. of alcohol, I put the required quantity (about thirty cubic centimeters)`into the boiler and light the lamp. Vapors will soon be generated, the tension of which balances the atmospheric pressure, and the mercury in the manometer will rise to a certain height,which I mark on the tube (or on a scale) with the num ber 10. If afterward the vapors of another liquid introduced into the boiler cause the mercury of the manometer torise to the same height, I conclude that thisliquid contains ten per cent. ot' alcohol. By a number of similar experiments I complete the graduation of the manometer-pipe, which ena- IOO bles me to ascertain the alcoholic contents of i any liquid.

It is now evident that the principle of my invention con sists in analyzing liquids by comparing the elastic power of their vapors with the elastic power ot' the vapors of another liquid which remains always the same. This principle is new and very valuable, for it at'- fords a very rapid and correct method of directly ascertaining the nature of liquids without requiring any correction from variations of temperature or of atmospheric pressure.

If liquids are analyzed by the ebnllioscopethat is to say, by ascertaining their boilingpoint-the want of a very sensitive and correct thermometer and the necessity of taking account of the barometric pressure constitute great obstacles in the way of the operator. To measure the tension of the vapors of a liquid directly-for instance, wine--by Geisslers vaporimeter or similar apparatus, any volatile elements except alcohol must be eliminated and the boiling temperature of the water into which the bulb of the vaporimeter plunges must be taken into account.

By my manometer all these obstacles are avoided; but to make the application of my principle easy in the hands of any operator I have constructed an apparatus which provides for great regularity of heat and accuracy of observation.

The lamp D for heating the boiler, together with the rest of my apparatus, is shown in Fig. 2, while Fig. 3 shows the construction of the lamp in detail.

tand t are two concentric pipes, joined at the bottom andformingan annularspaceforaround wick. Tube t reaches some millimeters above tube t, the wick being cut off at the level of the inner tube, t, so that it burns always on a constant length. To the outer tube, t, is soldered a lateral pipe, O, serving to support a receptacle or spirit-bottle, B, which feeds the lamp through a small opening, b, applied in the tube t. The alcohol from thc bottle fills the annular space between t and t up to the level N, corresponding to the upper edge of the opening of the bottle. After the lamp has been lighted the level of the alcohol sinks slightly below N, whereupon a drop ot' alcohol leaves the bottle and fills the wick-chamber up to its former level, N. The level of alcohol in the wick-chamber being thus practically constant, the flame will always remain regular.

Within the tube t is a third tube, t, not quite as high as t', and receiving the rod T, which supports the boiler, a small clearance being lel't between the tube t and the tube t, through which air has access to the iiame. The rod T, secured to the bottom of the boiler, rests on a projection, u, inside the tube t and secured to the latter. The tubes t and t are joined at the bottom, so as to close the wickchamber and form one movable piece, while the tube t is soldered to a base-plate, c, to which is also secured a cylindrical casing, w, fltting closely over the outer tube, t, and having a lateral slot passing from the top of the casing to the bottom of the tube O, so as to allow the movable piece (composed of tubes t, t', and O) to be inserted between tf and w from the top or to be removed at will. The base of the casin g w has also perforations x, through which air enters the annular space between t and t. The flame, being thus placed between two air-currents, is more regular and the combustion more complete than without an inner current. The method ot' supporting the boiler by the rod T-secures a correct and fixed position of the lamp with regard to the boiler.

For regulating the heating effect upon the boiler, I attach to the latter aconoidal shield, C, of sheet metal, which limits the direct contact of the hot gases of combustion with the boiler to the annular space y formed between the rod T and the shield C. Heat is transmitted to the boiler at the points of contact with the metal, but chiefly by the hot air inclosed at y, which forms a hot-air bath. This method of heating the boiler insures the desired regularity, and is an important feature of my invention.

At the beginning ot' the operation the vapors, ascending in the central pipe of the refrigerator, are condensed, and a column of mercury is raised in the manometer, which column approaches a constant level; but, to ascertain precisely the alcoholic proportion, we cannot, as in the ebullioscope, rely on this observation. fe must wait until vapors appear abundantly at the mouth ot' the central pipe. I then observe thc height of the mercury in the manometer and ascertain by means ofthe graduation direct the proportion of alcohol contained in the liquid.

By changing the-constant of the manometer any mixture from water to pure alcohol may be analyzed and the instrument made as sensitive as may be desired.

The mercury in the bulb may be replaced by a lighter liquid.

By a suitable choice of the constant and a corresponding graduation of the scale of the manometer it is possible to ascertain by this method the composition of any liquid.

Inasmuch as the indications of the instrument in its application for testing alcoholic liquids depend on the boiling-point ofthe latter, it may be called an ebulliometer, but as the height of the mercury-column (without taking into account the atmospheric pressure) corresponds entirely and under all circumstances with the tension of the vapors of the volatile liquid inclosed in the bulb, and serves primarily as a measure for the same, the instrument may be called a ma-nometer.7

What I claim is- 1. A manometer or ebulliometer consisting, substantially, of a vessel which contains mercury and a small quantity of volatile liquid, a pipe communicating with the mercury of the said vessel, and a scale for showing the height of the mercurycolumn raised by the vapors of the volatile liquid.

2. The combination of central tube, t, with tubes t and t, lateral pipe O, and receptacle IOC IIO

B, substantially as and for the purposes del In testimony whereof I have signed this scribed. specification in the presence of two subscri bin g 3. The combination of a boiler with a lamp witnesses. placed under the boiler and a rod held in the 5 center of the burner and supporting the boiler DOCTEUR L. PERRIER.

at a ixed distance from the flame, substantially as and for the purpose described. Witnesses:

4. The conoidal shield C for regulating the ED. DAUBRVILLE, 0. E., heating effect of the ame,'substantially as l ROBT. M. HOOPER.

xo described. l 

